Fluorescent probe studies of polymer‐solvent interactions

Ficht, Klaus; Fischer, Karl; Hoff, H.; Eisenbach, Claus D.

doi:10.1002/marc.1993.030140810

Cited by 7 publications

(4 citation statements)

References 2 publications

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“…For concentrations of 1 × 10 –5 , 2 × 10 –5 , and 5 × 10 –5 M, no LE emission was detected when the excitation power was above 500 μW (N 1 ), 500 μW (N 2 ), and 1 mW (N 3 ), respectively (see Figure ). The free-volume effect plays a major role in the TICT processes in polymer environment, because there will be more free volume for the twisting to occur in more diluted conditions than in concentrated ones. ,,, It is also possible to assume that the increase of the number of collisions of the polymer with the neighborhood in higher concentrations will contribute to deactivate the TICT species. Because of the sensitivity of the TICT emission to polymer environment, such system can be utilized as a probe to study the mobility of polymer segments …”

Section: Resultsmentioning

confidence: 99%

Optical Tuning of the Fluorescence Spectrum of a π-Conjugated Polymer through Excitation Power

et al. 2011

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The photophysical properties of a π-conjugated polymer containing 2,2'-bipyridyl alternated with 2,5-dihexyloxyphenylene units (PBPyDHP) are investigated experimentally in terms of the conditions used (solvent, concentration, presence or absence of molecular oxygen, and optical excitation power). The experimental results have suggested that the fluorescence from PBPyDHP can be tuned by proper selection of the experimental conditions showing only one or two emission peaks: 445 nm (blue) and 555 nm (green). The observed effects were interpreted in terms of the twisted intramolecular charge transfer (TICT) theory. This is the first experimental report showing the interconversion of an usual fluorescence, called locally emission state (LE), to a TICT state in second scale time by varying the excitation power; that is, even though the torsion of only one fluorophore occurs in a nano or picosecond scale, the global change (the interconversion for all fluorophores) has occurred in the second time scale.

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Section: Resultsmentioning

confidence: 99%

Optical Tuning of the Fluorescence Spectrum of a π-Conjugated Polymer through Excitation Power

et al. 2011

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“…However, for this case it is necessary to take into account that if the polymeric matrix is considered as the solvent of the f uorescent moiety, the solvent relaxation should be very restricted due to the high viscosity of the medium. In rigid systems, such as polymers below the glass transition temperature, the thermochromic shifts usually are batochromic [30][31][32].…”

Section: Study Of Thermal Transitions By Fluo Escencementioning

confidence: 99%

Fluorescent labels to study thermal transitions in epoxy/silica composites

ALBALA

2004

Journal of Colloid and Interface Science

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The analysis of the fluorescen response from the dansyl moiety as a function of temperature has been used to estimate the thermal transi-tions in silica particle/epoxy-based composite materials. Silica particles were surface-coated with 3-aminopropyltriethoxysilane (APTES) and 3-aminopropylmethyldiethoxysilane (APDES). 5-Dimethylamino-1-naphtalenesulfonyl chloride (DNS) and 5-dimethylaminonaphthalene-1-(2-aminoehyl)) sulfonamide (DNS-EDA) were selectively attached to the silanized silica particles and to the epoxy matrix respectively. The fluoresce ce results, interpreted in terms of the model of interpenetrating polymer networks, suggest that (i) independent of the silane coating, the interfacial region is slightly more rigid and heterogeneous than the epoxy bulk and (ii) the interface generated with APTES seems to be more flexibl than that obtained with APDES.

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“…In other works, the variation of the energy of the fluorescence emission with the temperature was used to determine thermal transitions as the T g [20,23,29,30].…”

Section: Introductionmentioning

confidence: 99%